The present invention relates to an artificial stone. More specifically, the present invention relates to a novel improved high-density artificial stone which has a granite-like or marble-like excellent texture and excellent properties such as a good surface hardness, a good surface abrasion resistance and the like, which is light-weight and has a high hardness and a high strength, and which can easily be adjusted to a desired thickness at a low cost, and it is to provide an artificial stone which is useful as a wall material, a floor material, other building materials, materials for construction, a stone pillar or the like.
It has been already known so far that a natural stone is pulverized to an appropriate size, and mixed with calcium carbonate and a resin, and then cured to form an artificial stone. That is, it has been stated that a starting stone powder, a resin and the like are mixed under reduced pressure, and the mixture is poured into a mold, withdrawn therefrom and cut.
Further, it has been also known that when an artificial stone is produced using a powder of a natural stone and a synthetic resin, it is required that the starting materials are used at a predetermined mixing ratio and these are thoroughly pressurized after they are put into a mold.
However, artificial stones obtained by these conventional methods involve a problem that the color and the deep feeling are not necessarily satisfactory even if using the natural stone powder.
The conventional artificial stone had a defect that the color tone of the surface always becomes dull. Thus, in the past, it was quite difficult to realize a transparent, deep and massy granite-like or marble-like surface.
This is presumably because characteristics of light reflection or absorption on a surface of an artificial stone vary greatly depending on the composition and the size and the formulation of the artificial stone powder, but such a standpoint has not been heretofore studied so much.
And the composition of the artificial stone greatly influences a moldability. There are problems that a fluidity for molding in a mold is lost depending on a size or a ratio of a natural stone powder to be incorporated into an artificial stone, a ratio of a binder resin or the like and bubbles remain inside a molded product, notably impairing qualities and a strength of a product artificial stone.
It is also considered that an amount of a resin component is increased to improve a fluidity and prevent occurrence of bubbles.
Meanwhile, that an amount of a resin component is increased to prevent occurrence of bubbles and secure a fluidity for feeding into a mold helps provide a fluidity and prevent occurrence of bubbles, but has an adverse effect on qualities of a resulting artificial stone.
The use of the resin component in a large amount leads to production of a resinous artificial stone product, and the resulting product is nothing more than one in which an artificial stone powder is present in a resin. Further, in view of properties, the product is closer to the starting resin than to the starting stone. Accordingly, although the resulting stone is called an artificial stone, the resulting product is merely a resin product that looks like a stone.
Then, the inventors of the present application has provided a composition in which an inorganic material component comprises a fine powder component having a larger particle diameter and a finely divided component having a smaller particle diameter and a mixing ratio of a resin is approximately 10% by weight or less regarding such a novel artificial stone that when a powder of a natural stone or the like is used as a material upon solving such defects of the conventional artificial stone, the resulting product is of a dense texture, has characteristics such as a transparent color tone, a deep feeling and a tone of a natural stone such as granite, marble or the like and is excellent in a moldability so that an optional shape such as a plate, a bar or the like can be provided.
This artificial stone has attracted attention as a stone which is excellent in the color tone and the characteristics.
However, in the later studies, a problem has remained that when attempts are made to provide this new artificial stone composition having a thickness, the costs are increased in the formulation of the inorganic material component and the production. Further, problems have been left that the molded product is made to have more improved properties or designing.
Under the above-mentioned circumstances, the present invention has been made. In order to solve the above-mentioned problems, the sum of a fine powder component of an inorganic material having a size of from 5 to 70 mesh and a finely divided component of an inorganic material of 100-mesh under is 89% by weight or more based on the total amount of the product. It provides an artificial stone characterized in that an artificial stone mixture containing the inorganic material mixture component comprising the fine powder component of the inorganic material and the finely divided component of the inorganic material and 11% by weight or less, based on the total amount, of a resin component is struck and integrated into a cured slab which has been cured.
Further, the present invention provides an artificial stone characterized in that a curable mixture is struck and integrated into a cured slab which has been formed from the above-mentioned artificial stone mixture.